I don't remember whether or not it's visualized for the player, though I too am of the opinion that it's a little confusing, particularly if coming from previous patches when it was possible. I don't know the reasoning behind locking off inventories during the intro, but I know it's because they're not technically companions at that point, only followers (lingo on how things work under the hood), and by proxy, I assume bugs were occurring because of fiddling with inventories during the intro. This is just personal speculation though, to be clear.
But yeah, it's not a bug then if that's the case and you can play on comfortably knowing that your game isn't broken
